Am I correct on septic pipe pitch?


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Old 07-04-19, 10:12 AM
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Am I correct on septic pipe pitch?

I have to run septic pipe 64' from my in-law-apartment and connect it to the main house septic line just before the septic tank. Am I correct to say that at 64' and a 1/4" pitch, my pipe would have a 9" pitch coming out of the in-law-apartment going to the septic tank?
 
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Old 07-04-19, 11:02 AM
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According to my math, 0.25x64=16!
 
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Old 07-04-19, 12:17 PM
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I'm a second vote for 16" fall in the drain line. I even checked Marq1's math.
 
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Old 07-04-19, 12:39 PM
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Yeah I double checked my math, I made a mistake. Well I can't get a 16" fall or I'll be below the septic pipe coming out of my main home, I'll probably have to go with a 2" outlet sewage pump. The problem I'll have there is the 4" main house line is only 1' below the ground before it goes into the tank. Seeing the 2" sewage pump line will be always full I'll have to come up with an idea to get it down deep enough so it doesn't freeze..
 
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Old 07-05-19, 04:59 AM
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You don't have to tie in where your main line exits the house. You can tie in close to the septic tank. That will be at a lower elevation and hopefully give you enough height. I would dig and find the inlet for your septic tank so you can measure the pipe's elevation there.
 
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Old 07-05-19, 07:13 AM
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That's where I planned to tie into was near the the septic tank line, my pipe is only 1' below the the ground, my cover only has a couple inches of dirt over it. Never had any problems with it freezing seeing it's only runs about 20 feet from the house. Not sure how I'm going to tie into it with a 2" waste pump line, only thing I can think of is digging the waste line lower so it won't freeze and then pumping up into the side of the main 4" line on an angle with a tee.
 
 

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